Nintendo showed The Legend of Zelda: Skyward Sword at its E3 press conference here Monday, finally unveiling the game that the company has been talking up for years — a new entry in its legendary adventure game series, designed from the ground up for Wii.

The Wii MotionPlus controller, which the game will require, will be used in a wide variety of ways. First and foremost, it’ll make Link’s sword-swinging a lot more accurate. Slash the Wii remote up and down, and he’ll do a vertical slice. Slash left to right and it’ll be horizontal.

I played the E3 demo of Skyward Sword following Nintendo’s press conference. Although it was only a brief experience meant to introduce players to the more complex control scheme, it showed that Zelda can integrate more complex swordplay while still feeling very much like a traditional Zelda adventure. This isn’t the Nintendo version of Dragon Quest Swords; this is the real thing.

Just as in the live demo that took place onstage this morning, I first encountered evil Venus flytrap plants. Some of them opened their mouths vertically, others horizontally, so that’s how I had to swing my sword to defeat them. I tried playing around with the controls. Although they didn’t work so well in the onstage Zelda demo, thanks to wireless interference, everything felt polished and perfect when I played. Swinging diagonally caused Link’s sword motion to match; when I put my hand down to the ground and swung upward in a giant arc, so did Link.

You can’t just twitch your hands around, but you don’t need to swing in giant arcs like Red Steel 2, either. If you select different items, you can get your sword back out just by swinging the controller.

The demo has massive control-scheme overlays on the screen at all times, telling you how to operate the game. I’m pretty sure this is just for the demo — I’d be surprised if you couldn’t turn it off for the final version, because it’s remarkably intrusive laid overtop the pretty graphics. Those are great, by the way — as the game zooms out, the textures become almost impressionistic, like daubs of paint.

Soon I went off on my own path and started messing around with the game’s items. Shooting a bow and arrow works a bit like Wii Sports Resort, but not entirely. After selecting the bow from the game’s helpful radial item-selection menu, you hold down the C button on the nunchuk to ready an arrow, pull back on the nunchuk and let go of the C button to fire. You don’t have to hold the Wii Remote in front of your face — you can keep it trained on the screen to aim with the pointer.

Shooting a slingshot is easier — just point and shoot.

Throwing bombs is fun. As they showed in the live demo, you can toss explosives in front of you or roll them underhand. I rolled a bomb toward a suspicious pile of rocks and exploded them to reveal a hidden door. Inside was a skeleton that wielded two swords, holding them in various defensive postures. He held one above his head and one to his right, meaning that I had to come in with my sword from his left.

After defeating the skeleton, I went over to an X marked on my in-game map and found a bigger boss character — a sort of giant scorpion with targets inside its claws. Again, you had to slash in the correct directions to take him out.

Since Skyward Sword won’t be available until 2011, we’ll have to survive on this brief demo for now. It’s impossible to tell what the game’s long adventure will feel like, but after all the years of hype, it’s good to see Zelda making progress.